The X-ray crystal structure of Gd₃N@C₈₀•Ni^II(OEP)•1.5(benzene) shows that the Gd₃N unit within the I_h C₈₀ cage is pyramidal, whereas Sc₃N@C₈₀, Sc₃N@C₇₈, Sc₃N@C₆₈, Lu₃N@C₈₀ and Sc₂ErN@C₈₀ have planar M₃N units.

The tetrahedral array of four scandium atoms with oxygen atoms capping three of the four faces found in Sc₄(μ₃-O)₃@I_h-C₈₀ is the largest cluster isolated to date inside a fullerene cage.

Based on the chemical reactivity differences between Sc ₃ N@ D _5h -C ₈₀ and Sc ₃ N@ D ₃ -C ₆₈ , Sc ₃ N@ D _5h -C ₈₀ was isolated and functionalized, giving rise to five new methano-derivatives.

Although there are 51 568 non-IPR and 24 IPR structures for C₈₄, the egg-shaped endohedral fullerenes Tm₃N@C_s(51 365)-C₈₄ and Gd₃N@C_s(51 365)-C₈₄ utilize the same non-IPR cage structure as found initially for Tb₃N@C_s(51 365)-C₈₄.